Pareto principle
The Pareto principle, or 80/20 rule, says that roughly 80 percent of results come from 20 percent of causes. For studying it means a minority of topics usually carries a majority of the marks. Find them with the exam blueprint and past papers, learn them first, then widen. It is a rule of thumb, not a law.
In more detail
It is named after the Italian economist Vilfredo Pareto, who noted around the turn of the 20th century that about 80 percent of the land in Italy belonged to about 20 percent of the people. Joseph Juran later popularized the name for the idea that a few causes drive most effects. The split is rarely exactly 80/20. The point is that effort and payoff are uneven.
In a course, marks cluster. Exams return to core ideas, the syllabus and exam blueprint show what each topic is worth, and past papers show which question types come back year after year. Putting your first hours into those topics earns a large share of the marks quickly.
The limits matter. If the exam is cumulative, or you must pass every section, skipping the other 80 percent can sink you. The 20 percent is also a guess until you check it against real evidence, and the rule says nothing about how to study, so pair it with retrieval practice. Use it to order your work, not to skip it.
Example
Dev has 15 lecture topics and 10 days. He lists the topics, then counts them across the last four past papers: five topics make up about 60 percent of the marks, and three of them appear every year. He studies those five first with practice questions, takes a timed practice test, then spends the remaining days on the other ten, weakest first. He skipped nothing. He only changed the order.
How to use it
- 1
List every topic on the syllabus or exam blueprint.
- 2
Check past papers or the mark scheme and note how many marks each topic got and how often it appears.
- 3
Mark the top handful of topics, roughly a fifth, that carry the most marks.
- 4
Study those first with active recall instead of rereading, until you can answer practice questions on them without notes.
- 5
Take a practice test, then spend the remaining time on the rest of the list, weakest topics first.
How StudyPDF does this
StudyPDF splits your course into topics and concepts, so the whole list sits in one place. Upload a past paper like any other file, then use quiz and practice exam results, which show a per-concept breakdown with the weakest first, to check that your high-value topics are really covered. The Plan tab places weak topics earlier in your schedule.
See also
Common questions
How do you use the Pareto principle for studying?
Rank your topics by how many marks they carry, using the exam blueprint and past papers. Learn the top fifth or so first with practice questions, then work through the rest in order of weakness. Treat 80/20 as a guide to sequence, not a reason to skip topics.
Is the 80/20 rule a good way to study?
It is good for ordering your time, especially when time is short, because it points you at high-value topics first. It is risky as a way to skip content, since the split is a rule of thumb and cumulative exams can test anything.
Put it to work on your own course
Upload your lectures and ask Bo. Cited answers, plus flashcards, exams, and more built from your material.